The present invention relates to a battery pack busbar module and more particularly to a technique of preventing the occurrence of abnormal noise at a joint portion between a resin busbar accommodating portion which accommodates a plurality of busbars which connect a plurality of batteries in series and a resin cover portion which covers an opening in the busbar accommodating portion.
A battery pack (a battery set or battery unit) in which a plurality of batteries are connected in series is used as a direct current power supply for driving a motor installed in an electric vehicle or hybrid vehicle. As described in Patent Literature 1, a battery pack like this is formed as a battery assembly in which a plurality of batteries are arranged to be bundled together in such a way that positive electrodes and negative electrodes of adjacent batteries are aligned alternately and are connected to each other in series by connecting the positive electrode and the negative electrode of the adjacent batteries with a conductor called a busbar. Then, the battery assembly or pack so formed is accommodated in a casing as required for use. In addition, the busbars which connect the batteries making up the battery pack together in series are accommodated in a box-shaped busbar accommodating portion which is made of an insulating resin material for installation in the battery pack. Then, in order to protect the busbars which are exposed from an opening side of the box-shaped busbar accommodating portion, a busbar module is used in which a resin cover portion is hinged to one of side edges of the box-shaped busbar accommodating portion which extend in a direction in which the batteries are connected together in series so as to be opened and closed.
As described in Patent Literature 1 or as the related art in the same literature, the cover portion is a resin plate-shaped member which is hinged to one of the side edges of the opening in the busbar accommodating portion which extend in the direction in which the batteries are arranged so as to cover the opening in the busbar accommodating portion. Additionally, in order to lock the cover portion to the busbar accommodating portion in such a state that the cover portion covers the opening in the busbar accommodating portion, a lock portion is provided. The lock portion is made up of a first engagement portion and a second engagement portion. The first engagement portion is provided on the other side edge of the opening in the busbar accommodating portion which extends in the direction in which the batteries are arranged. The second engagement portion is provided on the cover portion so as to correspond in position to the first engagement portion. Then, in this lock portion, by bringing the first engagement portion and the second engagement portion into engagement with each other, the cover portion is allowed to be locked to the busbar accommodating portion in such a state that the cover portion covers the opening in the busbar accommodating portion.
Patent Literature 1 JP-A-2000-333343
However, in the busbar module described in Patent Literature 1 above, nothing is taken into consideration to prevent a risk of abnormal noise occurring at the joint portion between the cover portion and the busbar accommodating portion when external vibrations are imparted to the busbar module which is installed in the battery pack mounded in a vehicle such as a motor vehicle.